#!/usr/bin/env python3

class DbHelper():
    def __init__(self) -> None:
        self.voicemodel = {}


    def addModel(self, identity, model):
        'return true false'
        if identity in self.voicemodel:
            return False
        else:
            self.voicemodel[identity] = model
            return True


    def delModel(self, identity):
        del self.voicemodel[identity]


    def getModel(self, identity):
        if identity in self.voicemodel:
            return self.voicemodel[identity]
        return None
